Board-lowering device.



4 I figpw 7 wa A. JOHNSON. BOARD LOWERING DEVICE.

APPLICATION FILED AUG. 7. I915. 1,177,705. Patented Apr. 4,1916.

A? 2 SHEETSSHEET 1.

A. JOHNSON.

BOARD LOWERING DEVICE.

APPLICATION FILED AUG. 7 1915- l,177,705. I Patented Apr. 4, 1916.

2 SHEETS-SHEET 2- H Joh nsoh wif'neooeo THE COLUMBIA PurjomMPu (0., WASHINGTON. D. C.

AXEL JOHNSON, OF EVERETT, WASHINGTON BOARD-LOWER ING DEVICE.

Specification of Letters Patent.

Patented Apr. 4, 1916;.

Application filed August 7, 1915. Serial No. 44,342. 7

To all whom it may concern Be it known that I, AXEL JOHNSON, a citizen of the United States, residing at Everett, in the county of Snohomish and State of lVashington, have invented certain new and useful Improvements in Board-Lowering Devices; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. 1

My invention relates to new and usefu improvements in board lowering devices and more particulaly to that class adapted to be used in connection with saw mills for lowering the board into engagement with the oflbearing table or rollers, and myobject is to provide, in connection with the offbearing rollers, pivotally mounted standards adapted to engage the board or cant as it is sawed from the log and lower the same upon the rollers.

A further object is to provide means at the lower ends of the standards to hold the board in engagement therewith.

A further object is to so mount the standards that they will swing in the arc of a circleand move to a position below the upper surface of the ofibearing rollers and out of engagement with the board. And a further object is to provide means for raising and lowering the standards.

Other objects and advantages will be hereinafter set forth and more particularly pointed out in the accompanying'specification.

In the accompanying drawings which are made a part of this application, Figure 1 is a transverse vertical sectional view showing the board lowering device in operative position. Fig. 2 is a vertical longitudinal sectional view through the supporting frame and device, and Fig. 3 is a top plan view" thereof.

Referring to the drawings in which similar reference numerals designate corresponding parts throughout the several views, 1 indicates the frame work which may be constructed in any preferred manner such as is in common use in saw mills, said frame work providing a support for the saw carriage 2 used for moving a log 3 toward the usual form of saw (not shown). Positioned adjacent one edge of the saw carriage is a frame 4 in which is mounted a plurality of offbearing rollers 5, one end ofthe' rollers having beveled gears 6 with tudinal centers between the straps 11, the

lower ends of said straps being pivotally mounted between ears 12 carried by bolsters '13, said bolsters extending transversely of the frame 4 and between the rollers. The lower end of each standard is provided with a lateral extension 14 in which is formed a slot 15 to receive the pivot pin 16 employed for pivotally attaching the'straps 11 to the ears 12, said slotvextending longitudinally of the extension 14 and limitsthe swinging movement of the standard. When the standard is first elevated, it is thrown to a substantially vertical position, as shown by dotted lines at 17 in Fig. 1, but when the board is sawed from the log and the lower edge thereof strikesthe frame 4, the board, in its outward'movement, contacts the upper end of the standard and swings the standard in the arc of a circle to the position shown in full lines in Fig. 1, this action throwing [the lower end of the standard outwardly and engaging a prong 18 at the lower end of thestandard with the lower edge of the board and as the prong projects below the edge of the standard, the board will be held in position against the face of the standard and as the standard swings on its pivot, the board is carried away from the edge of the frame 4 and out of the path of the log carriage.

The standard 10 normally rests in a horizontal position as shown by dotted lines at 19 in Fig. 1, the end of the standard rest ing upon the end of the bolster on which it is pivoted, and in order to raise the standbeing pivotally attached to a crank arm 23 carried by a shaft 24, said arm being fixed to the shaft in any suitable manner so as to causesaid shaft to rotate'whenthe' crank arm is moved in the arc of a circle. Also fixed to the shaft 24 is a-crank arm 25 to the outer end of which is pivotally attached a link 26, the upper end of the link being' shaft 24: and elevating the standards to the position shown by dotted lines at 17 in Fig. 1, the admission of the steam or air being controlled by a lever28 from the frame work 1. The lower end of said lever is connected with a valve 29 in such manner that when the lever 28 is swung back and forth, the valve will be opened and closed,

and so long as the valve 29 is open, the

piston 21 will be held at the upper end of the cylinder and the standards held in an elevated position. 7

As soon as the board is properly seated upon the standards, the valve 29 is closed, thereby releasing the pressure from below the piston so that the weight of the board upon the standards will swing said standards to a lowered position, the escape of the steam or air from the cylinder being so regulated that the standards will be caused to g adually descend, thereby depositing the board upon the rollers without delivering a blow to the rollers.

After the board has been deposited upon the rollers, the rotation of the rollers will carry the board to one end of the frame l where it is received by an attendant and properly disposed of for drying purposes, but should any obstructions, such as chips, or the like, prevent the board from traveling over the rollers, the board can be again raised by elevating the standards in the manner previously described. until such time as the obstruction is removed when the board canbe again lowered into engagement with the rollers.

In operation, while a board. is being sawed, the lever 28 is operated to open the valve 29so that steam or compressed air will be admitted to the cylinder 20 through the pipe 30, said pipe extending from a suitable boiler or compression tank (not shown). Upon the admission of steam or air into the cylinder, the piston 21 will be elevated to the upper end of the cylinder, thereby raising the standards 10 into position to receive a board cut from the log, said arms being held in their elevated position so long as the valve 29 is open. As soon as the board has been properly engaged upon the standard, the lever 28 is returned to its initial position, thereby closing the valve 29 and releasing the pressure below the piston,

but in view of the restricted exhaust port I 31 of the cylinder, it will require some time for all of the steam or air to leave the piston, thus permitting the standards to gradually assume their lowered position and de- 7 posit the board gently upon the rollers. V

This device can be readily attached to the frame of the offbearing minimum expense and by providing the same, the board can be more readily handled and will not injure the rollers when being deposited thereon. And it will likewise be rollers at a seen that the piston can be instantly 'oper- I ated at any time to raisethe standards into position to receive the board or elevate the same after it has been deposited on the rollers. V 7

Having thus fully. described my invention what I claim as new and desire to secure by Letters Patent of. the United States, is 2-,.

1. A board lowering device for ofi'bearing tables, comprising straps pivoted at their lower ends to the table, standards pivoted substantially at their longitudinal centersto said straps and adapted to swing independently thereof, means to limit the swinging movement of said standards forwardly or rearwardly, and means to raise and lower said straps and the standards pivoted thereto. p I

2. A board lowering device for offbearmg tables comprising 7 standards, pivotally mounted straps pivoted to said standards,

an engaging prong at the lower end of each standard, a slotted lateral extension at the lower end of each standard, a pin extending through said slot and limiting the swinging movement of the standards with respect to said straps, and means to raise or lower the straps and standards attached thereto.

3. A board lowering device for oifbearing' the strap to limit the swinging movement of.

the standard independently of the strap, a prong at the lower end of each standard,

and means to raise and lower said straps.

and the standards carried thereby.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

AXEL JOHNSON.

lVitnesses:

l VALTER EnIKsEN, F. B. MARTIN.

Copies of this patentmay be obtained for five cents each, by addressing-the Commissioner of Patents, Washington, D. G. 

